Windows 8 Upgrade on a Sony Vaio All-In-One?

Question for everyone:

Should I upgrade my Sony VPCL13S1E to Windows 8 Pro?

The Sony Vaio website can check whether they officially support certain older PC's and if so, offer some kind of upgrade pack with newer drivers etc. Unfortunately, my machine isn't one of them.

I downloaded the Microsoft Upgrade Assistant and there are a number of things that weren't compatible; bluetooth software, a few Sony applications, Secure Boot (whatever that is!) - The rest seems ok.

The question is; Does it matter that Sony have deemed my PC not 100% compatible, therefore will not/cannot supply all the relevant software and drivers?

My main concern is that some major hardware component will not be supported. I know bluetooth is not, but since I never use it, I couldn't care less.

Another question: Is there anyway to back track - return back to Windows 7 after installing Windows 8?